Abstract: Earth resistivity observation is from the DC power supply to more powerful pulse power supply with sinusoidal AC power supply, but the earth capacitive effects will cause observation error. This paper analyzes the effects of earth capacitance from the supply perspective. According to the method of equivalent circuit electronics, I put forward the concept of the equivalent capacitance of the earth. The relationship between equivalent capacitance of the earth and frequency and polar distance has been found based on experiment observations.

Key words: Equivalent capacitance of the earth, Resonance method, Alternating current injection method